Breastfeeding is recommended by the American Academy of Pediatrics, the World Health Organization and medical professionals worldwide as the preferred method for feeding infants during the first year of life. Human breast milk has significant health benefits that, to date, cannot be replicated by infant formula. Specifically, breast milk has been shown to reduce the incidence of infectious diarrhea, respiratory infections, otitis media, childhood obesity and other conditions. Breastfeeding has been shown to have health benefits for mothers too, such as by reducing the risk of postpartum bleeding and anemia. Risks are also lowered for ovarian and premenopausal breast cancer. Further, postpartum weight loss is enhanced in breastfeeding mothers. Other benefits of breastfeeding include its comforting effect upon both mother and infant. For these reasons, many health professionals feel that breastfeeding produces healthier, happier, infants and mothers, which is why breastfeeding is being promoted worldwide as a public health measure.
The need to know the amount of breast milk suckled by an infant is important to many lactating mothers. This information may help evaluate the infant's nutritional status, the need for breastfeeding guidance, and/or the use of infant formula, and is therefore important to the pediatrician as well. It is accepted that normal breast milk intake of an average infant starts at a few dozen milliliters during its first day of life, increases to a few hundred milliliters a day during the first week of life, and can reach approximately 700-900 milliliters per day afterwards. See J. Riordan and K. Wambach, “Breastfeeding and Human Lactation”, Jones & Bartlett Publishers, 4th ed. (2009).
Many mothers, due to their false impression and worry that insufficient milk is consumed by the infant, choose to discontinue breastfeeding fully or partially, and start using formulas. This is an unfortunate situation.
Devices for measuring the amount of milk expressed during breastfeeding have been proposed in the past. Many such devices adopt methods of fluid flow measurement, and typically include a flow or capacity meter mounted on the breast during breastfeeding, to measure the amount of milk flowing through. A few examples of such devices are shown in U.S. Pat. No. 5,827,191 to Rosenfeld, U.S. Patent Application Publication No. 2008/0039741 to Shemesh et al., and U.S. Patent Application Publication No. 2005/0177099 to Dahan. Other devices propose the use of flow gauges utilizing ultrasound measurements or piezoelectric devices. Other than accuracy problems, it is assumed that such devices did not gain much acceptance due to their intrusive nature, which interrupts the intimacy and simplicity of the mother/infant feeding and bonding process.
Other proposals include weighing the mother and/or infant or measuring the fullness of the infant's stomach before and after nursing, as disclosed, for example, in U.S. Patent Application Publication No. 2008/0097169 to Long, et al., U.S. Patent Application Publication No. 2008/0077040 to Ales, et al., and U.S. Patent Application Publication No. 2008/0077042 to Feldkamp, et al. Such proposals involve a substantial degree of inconvenience, which may explain their lack of widespread acceptance. In addition, experimental data suggests that weighing is an imprecise method for assessing milk intake in young infants. See 0. E. M. Savenije, P. L. P. Brand, “Accuracy and precision of test weighing to assess milk intake in newborn infants”, Arch Dis Child Fetal Neonatal (2006) 91:F330-F332.
Very commonly, pediatricians and nurses simply instruct worried mothers to count the number of wet (by urine) diapers per day, as some indication of the amount of breast milk suckled by the infant. 1-5 wet diapers per 24 hours during the infant's first week of life, and 6 or more wet diapers per 24 hours for older infants, is a rate commonly suggested by caregivers as indicating sufficient breast milk intake. Naturally, however, this diaper counting cannot be regarded as exact science, mainly since it does not provide a concrete measurement of actual volume of urine secretion per 24 hours.
Accordingly, there is still a long felt need for unobtrusive, convenient devices and methods of estimating the quantity of breast milk suckled by an infant.
Applicant's PCT Patent Application No. PCT/IB2012/052648, filed May 25, 2012, discloses devices, systems and methods for sensing the well-being of a subject, by detecting one or more physiological parameters. Applicant's PCT Patent Application No. PCT/IL2011/000615, filed Jul. 28, 2011, discloses system and methods for monitoring physiological conditions of a subject. These patent applications are incorporated herein by reference in their entirety.